Various peripherals such as printers, scanners, card readers, camcoders, network hubs, digital cameras, etc. have been commercially available as information technology has known a rapid, spectacular development in recent years. Such peripherals not only increase performance of computer but also enable a user to perform tasks that are not possible in the past by utilizing the computer and the associated peripherals. For instance, video conference through the Internet, editing digital images taken by a digital camera or camcoder, or the like is effected. This can greatly increase convenience and popularity of information products among consumers. However, installations of the peripherals can cause trouble to a user. Typically, a computer must be shut down prior to installing a desired peripheral in the computer. Next, connect the peripheral to an input/output (I/O) port at a rear of the computer. Then turn on the computer to install an associated driver. After installation, reset the computer to activate the peripheral for operating in cooperating with the computer. In view of this, its installation process is tedious. Further, a Plug and Play feature is not available. Also, a few I/O ports of the computer limits the number of peripherals that can be coupled to the computer. As a result, a performance of computer cannot increase as expected.
For solving this problem, seven major computer and/or telecommunication companies developed a rule of USB interface specifications recently. It is envisaged that faster signal transmission rate, Plug and Play (i.e., more convenient), and enhanced expansion capability of electronic products can be carried out by the rule of USB interface specifications. In general, a computer complied with the USB interface specifications can only provide two USB ports each capable of coupling to 127 peripherals via an external USB hub. Moreover, it is allowed to add or delete any peripheral depending on applications. Further, no driver installation or repeated resetting of computer is required. Hence, an installation process of peripheral becomes more user friendly.
For instance, an electronic product complied with the USB interface specifications is shown as a USB hub 11 in FIG. 1. The USB hub 11 is coupled to a USB port of a computer 10. A plurality of USB ports on the USB hub 11 are coupled to a modem 120, a CD-ROM 121 both complied with the USB interface specifications, and another USB hub 13. Also, a printer 140, a facsimile machine 141, a scanner 142, and a mouse 143 all complied with the USB interface specifications are coupled to the USB hub 13. In this manner, up to 127 peripherals can be coupled to the computer 10.
Typically, a peripheral 20 complied with the USB interface specifications coupled to the computer 10 is shown in FIG. 2. The peripheral 20 comprises a USB device controller 21, a microprocessor 22, an application chipset 23 of the peripheral, a plurality of memory devices (e.g., static random access memories (SRAMs) 24, flash random access memories (FLASH RAMs) 25, etc.), and other required electronic devices and circuitry (not shown). The USB device controller 21 acts to transmit or receive USB packets between the computer 10 and the peripheral 20. The microprocessor 22 acts to perform operations on the USB packets during transmission or receiving. The application chipset 23 of peripheral acts to control the peripheral 20 in response to instructions in the packets sent from the computer 10. As a result, a task assigned by the computer 10 can be achieved or alternatively a response packet generated to send back to the computer 10. The memory devices (e.g., SRAMs 24) act to store USB interface programs. Further, other memory devices (e.g., flash RAMs 25) act to store intermediate data created in the operations. Hence, respective peripherals can operate independently for achieving tasks assigned by the computer.
A latest CPU of computer can have a processing speed up to 1 Giga Hz. Also, a RAM installed in the computer is typically about 128 MB. This is sufficient to perform operations about running programs and software packages in a typical usage. Further, a multiprocessing can be performed with respect to different programs and software packages. Hence, a modern computer is very powerful indeed. However, as stated above, a maximum performance of a modern computer has not been completely demonstrated. Typically, only up to 20% of available features of computer is achieved. This is a waste. Thus, it is desirable to fully utilize available features of CPU and memory devices of computer for replacing microprocessors and memory devices of conventional peripheral with the same so as to obtain the following benefits; Perform operations involved in the transmission or receiving of the USB packets. Store USB interface programs and intermediate data created in the operations. Eliminate microprocessors and memory devices of a conventional peripheral that complies with the USB interface specifications. Reduce a burden on consumers in purchasing the peripherals.
Thus, it is desirable to provide a virtual processor through USB in order to overcome the above drawbacks of the prior art such as not fully utilization of available features of CPU and memory devices of computer.